body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Roboto", "Oxygen", "Ubuntu", "Cantarell", "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif
  margin: 0px;
}

div .banner {
  text-align: center;
}

div .banner h1 {
  font-size: 34px;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  margin: 0;
  line-height: 48px;
  color: #555;
  font-weight: bold;
}

div .banner p {
  font-size: 18px;
  line-height: 28px;
  color: #888;
  margin: 10px 0 5px;
}

.btn-group {
  display: inline-block;
  vertical-align: middle;
}

.btn-group:after {
  clear: both;
}
.btn-group:after, .btn-group:before {
  display: table;
  content: "";
}

.btn {
  display: inline-block;
  line-height: 1;
  white-space: nowrap;
  cursor: pointer;
  background: #fff;
  border: 1px solid #dcdfe6;
  border-color: #dcdfe6;
  color: #606266;
  -webkit-appearance: none;
  text-align: center;
  box-sizing: border-box;
  outline: none;
  margin: 0;
  transition: .1s;
  font-weight: 500;
  -moz-user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  padding: 12px 20px;
  font-size: 14px;
  border-radius: 4px;
}

.btn:active {
  color: #3a8ee6;
  border-color: #3a8ee6;
  outline: none;
}

.btn:focus, .btn:hover {
  color: #409eff;
  border-color: #c6e2ff;
  background-color: #ecf5ff;
}

.jumbotron {
  width: 890px;
  min-height: 200px;
  margin: 30px auto;
  position: relative;
  text-align: center;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: transparent;
  top: 0;
  left: 0;
}
